Devices that support the driving of the driver have been proposed. For example, Patent Literature 1 discloses a navigation device that acquires the driving tendency parameters of the driver and acquires the driving tendency parameters of a fellow passenger of the vehicle. The device disclosed in Patent Literature 1 calculates the difference between the driving tendency parameters of the driver and the driving tendency parameters of the fellow passenger and outputs information about the calculated difference as the traveling state of the vehicle to a display, thereby notifying the driver of the information. In this way, the device disclosed in Patent Literature 1 visually displays the difference between the driving tendency parameters of the driver and the driving tendency parameters of the fellow passenger as the traveling state of the vehicle such that the driver is aware of the difference. Therefore, the device disclosed in Patent Literature 1 is intended to provide a comfortable ride to the fellow passenger with driving experience.